NEW DELHI - Iran has asked India for $1.5 billion in back oil payments under the nuclear deal that provides Tehran some relief from Western sanctions, Indian sources with direct knowledge of the matter said on Thursday.

If the payments are approved, this could make India the third of Iran's major buyers, after Japan and South Korea, to start processing frozen back payments. The payments are contingent on Iran holding to its agreement to start curbing its nuclear program.

Indian refiners are holding about $3 billion in payments due the Middle Eastern crude producer, one of the sources said. Other funds owed to Tehran are held in a rupee-denominated account at India's UCO Bank. (Reuters)